According to the CDC's 1993 guidelines, <ref>http://www.cdc.gov</ref><ref>http://www.merckmedicus.com/ppdocs/us/hcp/content/merck/hiv/hivaids/aidsdefi.htmAIDS is defined </ref>as follows: | According to the CDC's 1993 guidelines, <ref>http://www.cdc.gov</ref><ref>http://www.merckmedicus.com/ppdocs/us/hcp/content/merck/hiv/hivaids/aidsdefi.htmAIDS is defined </ref>as follows: |